The "3 Mu" of Lean Design

By Jon Miller Published on September 27th, 2008

Elimination of the “3 mu” is at the heart of kaizen and lean management. The three Japanese words are muri, mura and muda. The latter is most commonly known as waste and categorized in the 7 types of overproduction, inventory, defects, transportation, waiting, motion and the waste of processing itself. These wastes are visible through observation, and while muri and mura are less visible we feel them more directly and are more aware of them than muda. Muri and mura are often the precursors to the wastes.
Muri is something that is unreasonable, overly burdensome or simply cannot be done. A classic example is to place 10 tons of load on a truck that is rated for 5 tons. That is not reasonable and will result in less than even performance. Mura is variability or unevenness and this often results from muri, or trying to do too much or having too little to do. Following the example of the truck, mura would be having only 5 tons to load on the truck on some days, but 20 tons on other days. The result of this variation may be that you try to load 10 tons, even though this is an unreasonable load. As a result of these things we have breakdowns, defects, excessive motion and other wastes.
All lean management, whether it be in manufacturing, logistics, healthcare or knowledge work focuses on getting rid of muri, mura and muda in order to improve performance. In order to be efficient about getting rid of waste and not always be reacting to the waste we see on the surface, we need to go upstream to how the products, services or the work itself is designed. We need lean design or “design for lean management” in the broadest sense of these terms.
Viewing work done in product design as a process helps us to identify and eliminate wasteful steps within the design process. If we think of design work in terms of a continuous and smooth stream of activity, we can imagine better ways of performing the work to get rid of rework, delays or overcomplicated process steps. Mapping the process as it is done today and redesigning it to focus on fast, high quality hand-offs will result in reduced cost and time to market.
Muri or overburden in the design process for example may be the need to work long hours to meet a tight schedule. We recognize this sort of overburden readily. Typically this comes from mura or unevenness in our workload. A design decision is made, a work package is release and suddenly we are twice as busy as the week before when we were waiting for the latest iteration to come back from another hand-off point. The end result of this mura and muri can be muda when we make errors under pressure, are forced to cut corners or release designs before they have been fully tested.
It can be particularly hard for people in the creative part of the design process to define what waste is within their work. The customer requirements may be unclear or undefined, yet some sort of work must still be done in the absence of clear requirements. That is one challenge. Another challenge may simply be one of belief that design work is essentially creative and cannot be standardized or quantified. Experience tells us that Pareto’s Law applies even here and that even within creative work we can find 80% of work that is repetitive within or between projects and 20% that is truly a unique combination of “never before” activities. Lean design, like much of lean elsewhere is a mental, not a technical challenge.
The focus of lean product development should be to streamline the routine and repetitive portions of this design work so that there is more time for the value-added or creative work. The creation or dusting off and use of checklists, standard items or design elements, documenting the appropriate and effective use of software design tools, and referring to a database of past lessons learned are only a few ways that the design process can use basic lean principles to improve knowledge worker productivity.
As design teams become more global the time and quality of hand-offs between members of the design team suffer. Design reviews may take more time or produce decisions of a lower quality, or no decision at all. It may simply be muri to try to connect a team of people in 5 different continents and time zones in a coordinated and speedy effort. At the very least it becomes harder to see and reduce the variability in work speeds and design process outcomes when members of the same design team do not occupy the same obeya (open room), much less the same continent. This too may be a gap that inexpensive video conferencing technology will eventually bridge, but that will only address 20% of the problem, the other 80% that is behavioral.
While having a global design team has advantages in terms of capturing lower cost or higher quality resources, this lack of visibility increases the cost tremendously in many cases. Redundant work, lost or non-transferred knowledge, an unawareness of true conditions on the gemba (place where the work is actually done) and certainly lost time in travel between sites when face-to-face meetings finally happen. Considering the cost of delays in speed to market, troubles during production ramp up, and the escape of defects into the market, the enlightened design leader should question if the costs and benefits balance out or whether there is in fact a net loss due to muri and mura imposed by a unconnected design team.
Even when the design teams works within the same country or same building there can be delays and stagnation in the flow of information and design work. The outsourcing of design tasks elements that are considered non-core or routine to contractors or suppliers is another way in which mura can be introduced in the unevenness or variability of work quality as well as muri or overburden, should these outside sources lack the level of technical or product knowledge and design capability. The pursuit of lower costs and the shifting of design work beyond the core internal team, intended to save cost, can result in more waste downstream.
Why go back to the obeya concept of having the whole team in one place, in this global economy? Why bring people together in a single open room to cooperate on design work, close to gemba or production site? In this day of off-shored-everything is it even feasible to reconnect these resources? Performance improvement relies on measuring target versus actual, and this is only effective when there is a place of work in which the flow of work can be observed and measured. Why do we want to measure creative work? Lean management is based on continuously improving (kaizen) based on a standard (regardless of how poor it may be), and lean design is no different.
Lean design should neither overly rely on nor abandon online collaboration tools for design teams. These tools need to be designed around processes which flow from person to person as directly as possible, based on agreed and standardized work contents, measured against targets and improved regularly through reflection on the performance gaps and root cause analysis. Trying to enable lean design any other way may simply be muri.

  1. Rafael

    November 7, 2010 - 12:17 pm

    Very good your comment about 3M`s. Congratulation

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